1,3-beta-glucan synthase subunit FKS1, domain-1. The FKS1_dom1 domain is likely to be the 'Class I' region just N-terminal to the first set of transmembrane helices that is involved in 1,3-beta-glucan synthesis itself. This family is found on proteins with family Glucan_synthase, pfam02364.

1,3-beta-glucan synthase component. This family consists of various 1,3-beta-glucan synthase components including Gls1, Gls2 and Gls3 from yeast. 1,3-beta-glucan synthase EC:2.4.1.34 also known as callose synthase catalyzes the formation of a beta-1,3-glucan polymer that is a major component of the fungal cell wall. The reaction catalyzed is:- UDP-glucose + {(1,3)-beta-D-glucosyl}(N) <=> UDP + {(1,3)-beta-D-glucosyl}(N+1).